不同改良剂对退化黄壤及其下渗水养分的影响

以添加了改良剂的退化黄壤为研究对象,通过种植莴笋―空心菜―莴笋的盆栽试验,对比分析添加生物质灰渣改良剂与其他改良剂对蔬菜产量、土壤养分的影响,并进一步研究了不同改良剂处理下,退化土壤下渗水养分状况,以期为综合评价改良剂的修复效果提供科学依据。结果表明:(1)NPKH(氮磷钾化肥配施灰渣)和NPKW(氮磷钾化肥配施生物质肥)处理的莴笋产量增幅最大;(2)经改良剂处理的退化土壤有机质的含量和p H提高,随种植时间增加,土壤有机质含量均下降,但NPKH处理的下降幅度最小,其次为NPKC(氮磷钾化肥配施草炭)处理;各改良剂处理对碱解氮的影响差异并不明显,NPKH处理较其他处理能显著提高土壤有效磷(P)、速效钾(K)含量,其中有效P较NPK(单施化肥)处理提高了190.0%~242.9%;(3)单施化肥在退化土壤上易造成氮素的流失(总氮(TN)流失浓度22.08~39.06 mg L~(-1)),NPKH、NPKW和NPKC处理的下渗水TN浓度均低于其他处理;NO_3~--N是土壤氮素损失的主要形式,其变化趋势与TN较一致,呈极显著的相关关系(p0.01,r=0.869);在整个盆栽过程中,土壤下渗水总磷(TP)、可溶性磷(DP)浓度呈极显著的相关性(p0.01,r=0.892),DP浓度占TP的60%以上;NPKH处理中的灰渣含有大量的磷元素,除供作物生长外,部分会随水流失,其下渗水中TP和DP分别为0.70~1.35 mg L~(-1)和0.67~1.27 mg L~(-1),明显高于其他处理,易造成水体富营养化。     

锯木灰渣改良退化菜园紫色土壤的效果研究

以重庆市九龙坡区白市驿镇蔬菜基地为试验平台,通过大田试验,研究了锯木灰渣不同施用量还田1年后对酸性紫色土改良效果,并进一步分析了锯木灰渣对土壤微生物群落及微生物碳、氮的影响,以期为紫色菜园退化土壤养分和酸化的修复提供合理措施,同时实现循环农业的可持续发展。结果表明:(1)锯木灰渣施用能显著提高蔬菜产量,且随着施用量的增加呈增加趋势,其中锯木灰渣施用量为18 000 kg hm~(-2)时,产量较未施用锯木灰渣(A0)处理显著提高了76.1%~121.9%;(2)经锯木灰渣处理的退化紫色土表层和亚表层的有机质含量和pH提高,尤其是锯木灰渣施用量为18 000 kg hm~(-2)的改良效果较佳,但是过高的锯木灰渣施用量处理对土壤交换性H~+、Al~(3+)效果反而下降,而施用量为12 000~15 000 kg hm~(-2)处理的效果较佳,其中表层土壤交换性H~+、Al~(3+)分别为0.19~0.20,0.63~0.67 cmol kg~(-1);(3)12 000~15 000 kg hm~(-2)的锯木灰渣施用量对土壤碱解氮和速效钾的提升效果较佳,18 000 kg hm~(-2)处理的有效磷含量最大,较A0处理增加了55.3 mg kg~(-1);(4)无论在表层土壤还是亚表层土壤中,细菌的种群数量分布最多,其次为真菌和放线菌,分别在12 000,9 000,6 000 kg hm~(-2)锯木灰渣施用量下的种群数量达到最大值;9 000~12 000 kg hm~(-2)处理对提高表层土壤微生物量碳含量较为明显,较A0显著提高了70.4%~78.7%,18 000 kg hm~(-2)处理的土壤微生物生物量氮(SMBN)含量最大(40.54 mg kg~(-1)),其次为9 000 kg hm~(-2)处理(34.32 mg kg~(-1))。综上,锯木灰渣施用量为12 000~15 000 kg hm~(-2)时对退化紫色土的改良效果较好。     

Applications of black walnut husks can improve orchardgrass and red clover yields in silvopasture and alley cropping plantings

Black walnut (Juglans nigra L.) produces both valuable lumber and a nut crop. Because of this, it is an important tree for agroforestry plantings in the Midwest USA. However, during processing of the nut crop, the outer tissue of the nut (husks) accumulates in great quantities. Applying this material to pastures is a possible method of disposal. However, black walnut has been implicated in allelopathic interactions with numerous plant species and may inhibit the growth of pasture species. Greenhouse and field studies and a chemical analysis of the husks were conducted to determine the effects of applying walnut husks to orchardgrass (Dactylis glomerata L.) or red clover (Trifolium pratense L.) pastures. Applying husks at rates up to 68 Mg ha⁻¹ to pot-grown orchardgrass resulted in root and shoot yields that were greater than in pots receiving no husks. Field studies indicated that orchardgrass and red clover benefited from the application of husks. For orchardgrass, significant increases in growth occurred when husks were applied at a rate of 34 Mg ha⁻¹ while red clover responded to rates up to 68 Mg ha⁻¹. A chemical analysis of husks indicated that significant quantities of N and K were present in walnut husks. A whole effluent toxicity test (WETT) indicates that runoff from walnut husk-treated pastures, at the rates used in this study, would not adversely affect aquatic organisms.     

JX生物调理剂饲喂肉猪试验

供试肉猪78头,随机分为三组,对照组(空白)、试验1组(新霉素115mg/kg、喹乙醇100mg/kg、阿散酸100mg/kg)、试验2组(JX调理剂0.2%),试验结果表明:第一阶段:试验1、2期末重,分别比对照组高1.34kg、1.07kg(P<0.05),试验组间差异不显著(P>0.05);第二阶段:试验1组期末重,比对照组高2.65kg(P>0.05),试验2组期未重比对照组高3.23kg(P<0.05),试验组间差异不显著(P>0.05);试验组料肉比均低于对照组,试验2组最低,比对照组降低0.2,饲料转化效率提高8.97%;试验2组比对照组每头猪多盈利48.8元,比试验1组多盈利10.28元;粪便中氮、磷含量试验2组明显下降,药物残留试验2组、对照组没有检出,试验1组猪肝阳性3个加、肉中阳性1个加。     

土壤盐碱改良剂施用量及施用时期研究

土壤盐碱改良剂在一定程度上能够起到松土、保湿、改良土壤理化性状的作用,促进植物对养分和水分的吸收,比传统的工程水利和生物改良方法简便易行、成本低、效果好,可较好的解决滨海盐渍土盐、板、瘦的问题,是一项改良治理滨海盐渍土的新措施.通过此技术的推广实施,可提高作物产量,扩大可利用农业土地资源,改善当地生态环境,推动经济发展,促进黄河三角洲的可持续发展.     

石灰、活性炭对镉污染土壤的修复效果研究

通过模拟铬(Cr,0～300 mg kg-1)污染土壤盆栽试验,研究石灰、活性炭及石灰+活性炭对铬胁迫下小白菜生长状况的影响及对铬污染土壤的修复效果。结果表明:受铬污染的土壤明显使小白菜受到毒害,但经石灰(L1、L2)、活性炭(C2、C3)及石灰+活性炭(L1C1、L2C2)处理均缓解了重金属的毒害症状,显著促进小白菜的生长,生物量较对照提高1～2倍(p<0.05)。3种改良剂相比,在相同Cr浓度处理下,活性炭对降低污染土壤中有效态铬的效果最好,与CK相比,有效态铬的含量降低至0.086 mg kg-1,降幅达77.36%。相关分析表明:小白菜叶部铬含量和根部铬含量与土壤有效态铬含量表现出显著的正相关(p<0.01),土壤pH与土壤有效态铬含量之间呈负相关(p<0.05),所以在铬污染的土壤中,可以提高土壤的pH,以减小土壤铬的植物有效性,使其向植物迁移的风险减小。     

Reducing Bioavailability and Leachability of Copper in Soils using Coal Fly Ash,Apatite, and Bentonite

Soils treated with two concentrations of copper (Cu; 200 and 400 mg kg^?1) were amended with three amendments (coal fly ash, apatite, and bentonite) at the rates of 1.5% and 2.5%, respectively. The effects of amendment application on the bioavailability and leachability of Cu in the soil were evaluated using the wheat uptake, single extraction, and sequential extraction tests. The addition of coal fly ash, apatite, and bentonite at the rate of 2.5% increased wheat biomass by 50.5%, 41.1%, and 61.7%, respectively. The application of amendments significantly (P < 0.01) reduced the Cu contents extract that will buy DW (deionized water), TCLP (toxicity characteristics leaching procedure), and DTPA (diethylenetriaminepentaacetic acid) in the soil. The amendments also reduced the water-soluble/exchangeable, carbonate, iron (Fe)–manganese (Mn) oxide, and organically bound fraction contents of Cu but increased the amounts of residual Cu in soil. Our results demonstrated that these amendments were effective in reducing the bioavailability and leachability of Cu in soil.     

Biological effects of native and exotic plant residues on plant growth, microbial biomass and N availability under controlled conditions

The leaf litter of six tropical tree species (Acacia holosericea, Acacia tortilis, Azadirachta indica, Casuarina equisetifolia, Cordyla pinnata and Faidherbia albida) frequently used in agroforestry plantations in Sahelian and Soudano-Sahelian areas were tested for their influence on soil nitrogen content, microbial biomass and plant growth under controlled greenhouse conditions. Half of the soil was planted with onion (Allium cepa L.) seedlings and the other half was not. Two herbaceous species, Andropogon gayanus and Eragrostis tremula, were also studied. Co-inertia analysis (CIA) and one-way analysis of variance (ANOVA) analysis showed that C. pinnata and F. albida leaf powder amendment induced the highest plant growth, whereas leaf powder of E. tremula is associated to higher microbial biomass and NH₄⁺ content. Higher onion seedlings growth is associated with higher concentration of nitrogen and lignin in leaf powders. Conversely, lower plant growth is associated to higher rates of cellulose, hemicellulose and phenols in leaves. Higher rates of cellulose and hemicellulose are associated with higher microbial biomass and NH₄⁺, whereas phenols are associated to lower microbial biomass. The results showed that amendment of A. holosericea leaf powder (high concentrations of phenol) to the soil resulted in a lower microbial biomass and lower onion seedlings growth. Data showed that the plant residue quality index (PRQI) could be a useful tool to predict the effects of litter materials on root growth in glasshouse conditions. The highest values on soil and plant parameters were recorded with C. pinnata litter. While powdered leaf material increased the accessibility of substrates to microbes, more research with C. pinnata leaf litter (under a wider range of ecological conditions) is needed. It could add deeper on its agronomic impact in the tropics.     

两种改良剂对酸化苹果园土壤环境及果树生长的影响

本试验研制两种改良剂,在田间设置不施用改良剂和施用改良剂两个处理,测定苹果单果重、可溶性固形物、果形指数、苦痘病发病率以及土壤pH、有机质、元素含量、病原镰孢菌的数量和真菌群落结构的变化。结果表明,两种改良剂对缓解苹果园土壤酸化均具有良好的效果,其中德州改良剂效果最为显著。与对照相比,经德州改良剂处理后,苹果单果重平均提高39%,果形指数达到0.83以上,可溶性固形物达到14%以上,苦痘病发病率降至1%以下,土壤pH平均提高1.70,土壤有机质平均提高9.00 g/kg,且降低土壤有效Cu、有效Mn以及植株体内全Cu、全Mn含量,提高土壤交换性Ca以及植株体内全Ca含量,降低病原镰孢菌数量,优化真菌群落结构。综上,两种改良剂可有效缓解苹果园土壤酸化,促进果树生长。     

不同改良剂对滨海盐渍土盐碱指标及作物产量的影响研究

针对江苏滨海盐渍土的特点,采用5种土壤改良剂,通过田间试验分析了不同处理土壤盐碱指标的变化状况,并结合作物产量筛选出适宜的改良剂。结果表明：禾康、康地宝、腐殖酸处理后,土壤盐分含量、pH、总碱度和钠吸附比（(SAR）)较对照都有所降低,其中腐殖酸处理降低量最多,各指标分别为0.53 g/kg、0.16、0.170 cmol/kg和2.61;石膏处理后,土壤盐分含量增加0.16 g/kg,但pH、总碱度和钠吸附比与对照相比分别降低0.08、0.09 cmol/kg、3.33;金满田生物菌剂处理后土壤盐分、pH、总碱度和钠吸附比与对照相比差异不明显。改良剂处理后作物产量都有所提高,其中腐殖酸处理较对照增加最多,油菜和玉米分别增产15.68% 和9.15%。